The affordable, family-friendly restaurant opened at 66 E. Ohio St. in the former Harley Davison gift store Nov. 4. Aria Group architect Eduardo Mani said he read in Chicago papers that people were waiting in line for hours on opening day to get in to the new burger and hot dog joint with a 150-max capacity.

The Oak Park architecture company has worked on Shake Shack location concepts since 2010, designing the Westport, Conn. and University City, Pa. spots.

Even though all Shake Shacks, a chain founded by New York restaurateur Danny Meyer 10 years ago, aim to be functional spaces that follow ADA regulations, all the locations are a bit different, Mani said.

"In the Chicago location we wanted to keep it industrial, but warm it up with woods."

There are also some Chicago specific twists to the menu. Foodies looking forward to visiting the new River North addition will find a Shack-cago Dog and a Salted Carame'L' Concrete to try.

Aria Group is working on another Chicago area Shake Shack scheduled to open at Old Orchard Mall in August 2015, Mani said. The city will see its second Shack next year as well near the Art Institute.